Sylvia left 7 D.F. sometime between 10 October and December, 1914 and was made one of thirty destroyers attached to the four Battle Squadrons operating in Home and Atlantic Waters.[15] This assignment evolved into an attachment in support of the Grand Fleet, with the number of destroyers paring back to ten by mid August, 1917.

On 29 September, 1917, under the command of LieutenantR.N.R.Peter Shaw, she and Arab raced out of Lerwick in a belated effort to assist in Tirade's destruction of UC 55. Sylvia nonetheless fired three rounds from her 12-pdr., claiming hits that other sources discounted.[16]

In January, 1918, Sylvia was one of eleven destroyers operating out of the Firth of Forth. This force acquired the name of Methil Convoy Flotilla some time in February. In April, 1918, Sylvia left the Methil Convoy Flotilla for the Seventh Destroyer Flotilla, which was operating out of the Humber as part of East Coast Forces. She would serve with that formation through the end of the war until it was re-formed around a core of modern destroyers in February, 1919. Sylvia was sent to the Humber await disposal.[17]